Injection stretch blow-molding systems are well known in the art. A variety of different sophisticated injection stretch blow-molding machines have been developed through the years.
Most known injection stretch blow-molding machines use a vertical clamp and complicated rotary devices. They are very cumbersome in manufacturing and require very expensive tooling. In addition, they vertically move very heavy weights during opening of the clamp and then have to decelerate with the same weights, during closing of the clamp. The necessity to lift and decelerate free falling heavy weights during clamp opening and closing makes machines with vertical clamps energy inefficient compared to machines with horizontal clamps.
In addition, there is a common trend in the latest machine technology to use all electric machines because of many advantages they have over hydraulic machines. To provide the necessary clamp tonnage all electric machines must use toggle clamps. An injection stretch blow molding machine with horizontal clamps is perfectly suited to be an all electric machine with a toggle clamp. Vertical clamps make it very difficult to adapt the toggle clamp set up, and by that, hinders the ability to mass produce all electric injection stretch blow molding machines. The vertical clamp set up historically started on the assumption that parisons are soft after they are removed from the injection mold and because of this they should be transferred in a vertical position to prevent distortion during transfer from the injection mold to the blow mold. In reality, parisons made in the stretch blow molding process are rapidly cooled in the injection mold to avoid crystallization. Parisons cooled to this condition are rigid enough to be transferred in the horizontal position without being distorted.
A stretch blow-molding machine with a horizontal clamp and shuttle plate moving perpendicular to the machine axis is shown in U.S. Pat. No. 4,376,090. However, this patent does not provide a description of how different parts of this machine are formed and operate, and shows the parison supported by the core pin during its transfer from the injection mold to the blow mold. Moreover, this patent does not have independently operating stretch stations, and stretching of the parisons is performed by closing of the machine clamp. This approach makes it impossible to control the sequence between introduction of blow pressure and mechanical stretching of the parison. It is also difficult in this instance to control the speed with which the mechanical stretching is done, and it is impossible to introduce air before the mechanical stretching begins. The speed of stretching in this patent is tied up with the speed of clamp closing which by itself requires a completely different set of considerations. Injection and blow stations of this invention are sitting on the same platen. In the injection stretch blown molding process, the length of the blown product is much greater then the length of an injected parison. In the set up, described in the above patent, the stack height of the injection mold should be considerable to mach the height of the bottle produced in the blow mold which due to stretching of the parison can be 2.5 to 3 times as long as the initial parison.
It is an object of this invention to provide an injection stretch blow-molding machine with a horizontal clamp for the purpose of manufacturing injection stretched blow molded products of various sizes and configurations.
It is another object of this invention to provide an injection stretch blow-molding machine where a horizontally positioned parison is being transferred from the injection mold to the blow mold by its neck portion.
It is still another object of this invention to provide an injection stretch blow-molding machine with a new and improved shuttle assembly, moving along the machine axis, and a shuttle plate moving perpendicular to the axis of the machine.
It is yet another object of this invention to provide an injection stretch blow-molding machine with a new and improved core pin assembly formed on the movable platen of an injection-molding machine with a horizontal clamp.
It is a further object of this invention is to provide a new and improved injection stretch blow-molding machine with new and improved blow-mold assemblies positioned next to an immovable platen for the purpose of manufacturing containers of a substantial length, without increasing the daylight of the machine.
It is a still further object of this invention to provide an injection stretch blow molding machine with blow molds formed with a tapered locking device to provide an alignment between the blow mold and the neck ring during clamp closing.
It is a yet further object of this invention to provide a new and improved injection stretch blow-molding machine with new and improved stretch stations formed on the machine movable platen.
It is a yet further object of this invention to provide a new and improved injection stretch blow-molding machine with interchangeable in the machine tooling components.
In accordance with an aspect of the present invention, an injection stretch blow molding machine with an extruder and a horizontally opening clamp is utilized for manufacturing of injection stretch blow molding articles of a different configuration and sizes. The injection stretch blow molding machine includes a stationary machine platen; a movable machine platen which is movable toward and away from the stationary machine platen along a machine axis, to close and open a mold; opposite support structure mounted moveably on machine tie rods; a shuttle assembly mounted between the opposite support structure, for movement along the machine axis, the shuttle assembly including a shuttle plate movable perpendicular to the machine axis; at least one stripper bushing mounted on the shuttle plate for movement therewith, slides movably mounted on the shuttle plate for movement with the shuttle plate and movable toward and away from each other in close proximity to a front surface of the shuttle plate, the slides heaving at least one neck ring; an injection mold with a hot runner manifold mounted on the stationary platen; at least one blow mold assembly with blow mold halves defining blow mold cavities, at least one blow mold assembly fixed relatively to and positioned adjacent to the stationary machine platen; and at least one stretch station fixed relatively to and positioned adjacent to the movable platen including stretch rod adapters for guiding the stretch rods and removing a blown bottle from the blow mold during opening of the machine; a stripper station mounted on the shuttle plate; and at least one stripper bushing fixed on the stripper station, for removing a blown bottle from the stretch rod adapters during clamp opening. Each stretch station includes stretch rods mounted on the plate reciprocally movable along the machine axis formed to stretch the parisons inside the blow cavity in accordance with the sequence of the machine.
Further, there is a retainer plate mounted on movable platen and at least one core pin mounted on the retainer plate; the retainer plate formed with openings to bring temperature controlled liquids to the core pin.
Also, at least one stretch rod adapter is formed on the retainer plate adjacent to the core pin with openings formed in the retainer plate to bring gases through stretch rod adapter to blow the parison into a bottle.
The opposite structure, for supporting the shuttle assembly, is riding on the machine tie rods and made to move with and away from the movable platen along the machine axis, in accordance with the sequence of the machine operation.
In one embodiment, at least one cure station is formed adjacent to the stationary platen and in between the injection mold and blow mold assemblies.
This invention thereby involves injection stretch blow-molding machines, and contemplates forming the machine with a horizontal clamp and shuttle assembly, moving along the tie rods of the machine. The shuttle plate is a part of a shuttle plate assembly and is moving perpendicular to the machine axis during opening of the clamp in accordance to the sequence of machine operation. Two blow mold assemblies are located on both sides of the immovable platen of the machine clamp. An injection mold with a hot runner manifold is formed on the stationary platen of the machine. The injection mold is temperature controlled. Two stretch stations are formed on both sides of the movable platen and equipped with interchangeable in the machine stretch rods. This invention contemplates the injection stretch blow-molding machine having a take-off device formed to remove finished products from the machine.
The invention accordingly is comprised of the features of construction, combination of elements, and arrangements of parts which will be exemplified in the system, device, and article of manufacture hereinafter described and of which the scope of application is as elucidated hereinafter, as will be indicated in the appended claims. In this regard, numerous alternatives within the scope of the present invention, besides those alternatives, preferred embodiments or modes practicing the invention supra, and those to be elucidated, will occur to those skilled in the art.
Others objects, features and advantages of the invention in its details of construction and arrangements of parts will be seen from the above, from the following description of the preferred embodiment when considered with the drawing and from the appended claims. In addition, these and other objects and advantages of the present invention will become evident from the description, which follows.